154 CLASSIFICATION OF THE MICRO-ORGANISMS. 



with simultaneous death of the cells ; further, it readily 

 forms spores, its cells approach more and more the form 

 of spindles or ellipses, and are not ahle to cause thrush 

 when inoculated on fowls. The thrush fungus, on the 

 other hand, sets up marked fermentation with simul- 

 taneous luxuriant vegetation, forms no spore^, the cells 

 are more spherical, and it causes distinct thrush when 

 pure cultivations are inoculated on the crop of fowls. 

 The experiments on animals require to he extended and 

 completed, in them more especially lies the decision of 

 the question of identity. 

 Rose-coloured Pigment-producing yeasts are also known : 



Saccharomyccs glutinis (Cryptococcus gl.) Cells 

 spherical, oval or short cylinders, 5 11 /A long, 4 /A 

 broad, isolated or united in pairs. Cell mernhrane and 

 contents colourless in the fresh state, when dried and 

 again moistened they show a faintly reddish nucleus 

 in the centre. Spore formation unknown. Forms rose- 

 coloured slimy coatings on slices of potato, nutrient jelly, 

 &c. In the latter, when inoculated by pushing a needle 

 into the substance of the gelatine (puncture cultivation) , 

 the growth beneath the surface has the appearance of 

 white threads shooting out on all sides ; marked growth 

 and the production of colouring matter only take place 

 on the surface. The colouring matter is not altered by 

 acids and alkalies. The pink torula is apparently very 

 widely distributed ; in our neighbourhood one or more 

 colonies appear on every jelly plate exposed to the air 

 for a short time. According to Hansen there are three 

 different varieties of pink torula, of which one forms 

 ascospores, while a second gives rise to germinating 

 tubes of peculiar form when the nutriment is insuffi- 

 cient. 



A brownish-black yeast is also at times present in 

 water and air; a more detailed description cannot as 

 yet be given. 



